Drill stem drive



i Jan. 16, 1940. J. A. SMETHERS DRILL STEM DRIVE' Filed Ja. 18, 1938 WIIIIIIIIIIIIIII INVENTOR Yt %Aa U ATTORNEY James A. Smei'he damage to the drill V other edge the link 'portion l8 on the 2 member The' ends of the channels may be closed, as indicated by the end flanges 8 and ll.

Extendlng across the arms of the channels are a plurality of pivot pins 9 arranged in vertical sequence. Upon these pins are rotatably mounted the gripping rollers 6. In the present instance, each roller rack 5 is shown as accommodating five rollers.

The rollers 6 are preferably made of hardened material and their peripheries are made concave, as illustrated most clearly in Fig. 2. In order to insure uniform gripping without deformation or stem pipe l, the peripheries of the rollers may be provided with diagonal knurls.

In order to grip the stem I, the roller racks 5 should be urged inwardly in a radial direction against the stem I. When these rollers are in gripping relation, a driving connection exists between the casing 2 and the stem l. At the same time, however, it is possible to raise or lower the stem l through the rollers, irrespective of this grip. There is no material friction to overcome in performing this operation, for the bearings of the rollers 6 may be well lubricated. Accordingly, the usual weight indicators may operate without appreciable error.

The rotation of the casing 2 acts automatically to urge the roller racks 5 inwardly against the pipe I. In order to accomplish this result, the roller racks are joined to the inside of the casing 2 by toggle mechanisms, and furthermore these racks are guided in radial guides in the top and bottom of the casing 2. One of these radial guides is shown to best advantage in Fig. 3. It comprises a plate o having the radial guideways i I therein. In these guide ways are disposed the bottom flanges 8 of the racks '5. A similar radial guide plate !2 is disposed upon the shoulder l3 adjacent the top of the casing 2. In this guide plate l2 are located the upper flanges M of the roller racks 5. The guide plates !0 and !2 are not permanently joined to the casing 2, but are free to align themselves in accordance with the requirements of the roller rack motion. However, they insure that the rollers carried by the roller racks squarely engage the drill stem I. A

cover IS may be disposed over the casing 2 and joined to it as by the aid of the bolts lE passing through the contiguous flanges of the cover |5 and casing 2. In this way the Operating mechanism is substantially enclosed.

The toggle mechanisms for Operating the roller racks 5 may best be described in connection with Figs. 1 and 2. Each of the roller racks is joined to the casing 2 by the aid of a ling I'. This link has an enlarged edge !8 forming a hinge connection with the inner wall of casing 2. At its ll is provided With a similar enlarged hinge portion !9, accommodated in a socket member 20 extending the full length of the rack 5.

As casing 2 is rotated in a clockwise direction, as viewed in Fig. 2. there is a straightening-efect of the link l'l, tending to align it in a radial direction. The resultant toggle effect urges the corresponding roller rack 5 inwardly with relation to its guides in the guide plates o and !2. The resultant effect is a simultaneous gripping of the drill stem l by all of the rollers in all of the i'acks.

In order to insure against the Creation of too much friction by resting of the enlarged hinged shoulder 2| of the casing 2, there may be inserted a number of thrust ball bearings 22 contacting with the bottom of the enlarged portion IB.

The rotation of casing 2 in the proper direction automatically causes the gripping action to take place. There is no need for manual adjustments or the like, because all of the racks are substantially uniformly advanced and retracted. Furthermore, as the stem i is fed downwardly or upwardly, the rollers can accommodate themselves to the required peripheral diameter of the stem, which may not be uniform. The action of all of the rollers is uniform. v

The mode of operation of the device is apparent from the foregoing. In order to secure the toggle action, of course the link I'I and the rack 5 would not come into exact radial alignment with the axes of the stem I, no matter how small in diameter this stem may be. However, as the stem l encounters greater resistance, the eflect of this resistance is to cause the toggle mechanisms to urge the roller racks 5 more strongly against the stem I. In this way there is never any loss of grip, in spite of the fact that the stem l may easily be raised or lowered through the well lubricated rollers 6.

In order to insurethat each roller rack 5 engages instantly, as well as simultaneously with the racks, upon movement of the case 2 in a clockwise direction, a compression spring 23 is arranged between the case and each of the roller racks. These springs are efiective to urge the toggle toward its straight position and bring the rollers 6 into contact with the drill stem l at all times, thus immediately upon movement of the case, the rollers grip the drill stem. Upon termination of the clockwise movement, a slight movement of the' case in the opposite direction will free the rollers from the stem, except for the small pressure resulting from springs 23.

What is claimed is:

1. In a drive for a rotary drill stem, a plurality of angularly spaced grippers adapted to engage the stem along a substantial length thereof, up-

' per and lower radial guides for the grippers, and

means forming a toggle joint mechanism with each gripper to urge it toward engaging position.

2. In a drive for a rotary drill stem, a plurality of angularly spaced grippers adapted to engage the stem along a substantial length thereof upper and lower radial guides for th` gr ppers, and a common rotary member for urging the grippers inwardly and for imparting rotation to the stem.

3. In a drive for a rotary drill stem, a plurality of roller members having gripping faces adapted to contact with the stem, and also having axes extending in a direction transverse to the stem axis, upper and lower guides for the roller members, a rotary member encompassing the roller members, having an axis coincident with the stem axis, and mechanism for joining the rotary member and the roller members for causing, upon rotation of the rotary member, the roller members to be urged into gripping relation to the stem for driving it.

4. Ina drive for a rotary drill stem, a plurality of roller members adapted to contact with the stem, and also having axes extending in a direction transvers-e to the stem axis, upper and lower guides for the roller members, a rotary member encompassing the roller members, having an axis coincident with the stem axis, and a toggle link for each roller member and joinng it to the rotary member.

having gripping faces i .t. :in a drive for a rotary drillstem, a casing adapted to be rotated by a rotary mechanism and through which a drill stem is adapted to extend, a plurality c! roller racks angularly spaced about the axis of the stem and within the casing, each of said racks pivotally supporting a piurality of rollers adapted to engage the stem, upper and lower radial guides-for the racks, and a link` connection between each rack and the casing, said link connection extending along the length of the respective rack and having a hinge connection with the ra'ck and with the casing. i

6. In a drive for a rotary drill' stem, a casing adapted to be rotated by a rotary mechanism and through which a drili stem is adapted to extend, a plurality or i roller racks angularly spaced about the axis of the stem, and within the casing, upper and lower radiai guides for the racks, and a link connection between each rack and the casing, and having a-hinge connection with the rack and with the casing.

7. In a drive !or "a rotary drill stem, a casing adapted to be rotated by a-rotary mechanism and through which a drill stem is adapted to extend, a plurality of roller racks anguiariy spaced about the axis of the stem, and within the casing, radial guides !or the racks, a link connection between each rack and the casing, and having a hinge connection with the rack and with the casing, and means resiiently urging to keep the linkconnection toward a radial thrust position.

8. In a drive for a rotary dri stem, a casing adapted to be rotated by a rotary mechanism and through which a dril stem' is adapted to extend, a plurality or roller racks angularly spaced about the axis of the stem, and within the casing, radial guides for the rocks, and a link connection between each rack and the casing, and having a hine connection with the rock and with the casing, each of said racks including a plurality of supper rolers pivot any mounted on anes transverse to the stem axis, and in vertical arrangement.

9. In a drive for arotarydrm stem, acasing adapted to be rotated by a rotary mechanism and through which a drill stem is adapted to extend, a plurality oi roller racks anguarly spaced about the axis o! the stem, within the -casing, and connections from the casing to the racks arranged to exert a radia thnst upon the racks and toward the stem, upon rotation -ot the casing in one direction, and means to 10. In a drive for a rotary driii stem, a casing adapted to be rotated by a rotary mechanism andthrough which a drilistem is adapted to extend, a plurality of roller racks ang ariy spaced about the axis of the stem and ithin the casing, each of said rocks pivotally s pporting a piurality o! roliers adapted to engage the stem, upper and lower connections from the casing to the racks arranged to exe'rt a radial thrust upon the racks and toward the stem, upon rotation of the casing in one direction, means resiliently urging the connections in a direction to move the racks toward the stem, and means to maintain the angular spacing between the racks substantially constant, comprising upper and lower guides.

11. The combination as set forth in claim 9, which the connections and the racks form a series of toggle mechanisms that 'tend to straighten when the casing rotates in one direction.

12. In a drive for a rotary drll stem, a casing adapted to be rotated by a rotary mechanism V and through which a drili stem is adapted to extend, a plurality of roller racks angulary spaced about the axis of the stem and within the casing, each of the racks pivotaily supporting a. plurality of rollers adapted to engage the stem, means gu'ding the racks for radial movement and to maintain the angular spacing between them substantially' constant, said means comprising upper and lower members rotatably supported in the casing coaxially with the drill stem, and at opposite ends of' the racks respectively, connections between the casing and the racks arranged to exert a radial thrust upon the racks toward the stem upon rotation of the casing in one direction, and means resiliently urging the connections'in a direction to move the racks toward the stem.

13. In a device adapted to form a. driving connection between a rotary machine and a drili stem. a cylindrical casing adapted to be connected to the rotary machine substantiaily coaxiay with the stem, upper and lower members rotatably carried by the casing and coaxiai therewith, each oi' said members having a plurality oi' guides radial to the axis of the casing, gripper racks extending between the members and slidably supported in said guides, each of said rocks carrying ripping means adapted to enxage the stem upon inward radial movement o! the rocks. and means interposed between the casins and the rocks whereby relative rotation between the casing and the guide members will be effective to move said racks inwardy.

- JAMES A. SHEH-Ilias.- 

